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1.
J Microbiol Immunol Infect ; 49(4): 494-501, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25442871

RESUMEN

BACKGROUND: To determine whether the presence of a capsule regulator gene [i.e., regulator of mucoid phenotype A (rmpA) gene] contributes to virulence on extended-spectrum ß-lactamase-producing Klebsiella pneumoniae (ESBL-KP) with serotype non-K1/K2 strains. METHODS: Twenty-eight ESBL-KP and non-ESBL-KP isolates were collected from the Tri-Service General Hospital (Taipei, Taiwan). The impact of the virulent rmpA gene in different capsular polysaccharide serotypes on ESBL-KP and non-ESBL-KP isolates was studied by a neutrophil phagocytosis reaction, a serum bactericidal assay, and an animal survival model. RESULTS: Resistance to broad spectrum antibiotics was more prevalent in ESBL-KP strains than in non-ESBL-KP strains (p < 0.01). The ESBL-KP strains had different molecular patterns from non-ESBL-KP strains, based on pulsed-field gel electrophoresis. The frequency of serum-resistant isolates was the highest among ESBL-KP strains with rmpA (i.e., rmpA(+)) [71.4% (5/7)] than among of non-ESBL-KP rmpA(+) strains [42.8% (6/14)], ESBL-KP strains without rmpA (rmpA(-)) [33.3% (7/21)], and non-ESBL-KP rmpA(-) strains [14.2% (2/14)]. The most significant increase in neutrophil resistance occurred in the ESBL-KP rmpA(+) strains in comparison to the non-ESBL-KP rmpA(+), ESBL-KP rmpA(-), and non-ESBL-KP rmpA(-) strains (p < 0.01). The results of the animal survival model were compatible with the neutrophil phagocytosis reaction and serum bactericidal assay. CONCLUSION: We conclude that the pathogenic potential is greater in rmpA(+) ESBL-KP strains than in rmpA(-) ESBL-KP and non-ESBL-KP strains.


Asunto(s)
Cápsulas Bacterianas/genética , Proteínas Bacterianas/genética , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/patogenicidad , beta-Lactamasas/genética , Animales , Antibacterianos/uso terapéutico , Electroforesis en Gel de Campo Pulsado , Humanos , Infecciones por Klebsiella/tratamiento farmacológico , Klebsiella pneumoniae/efectos de los fármacos , Masculino , Ratones , Ratones Endogámicos BALB C , Neutrófilos/inmunología , Fagocitosis/genética , Fagocitosis/inmunología , Serogrupo , Taiwán
2.
J Microbiol Immunol Infect ; 45(2): 141-6, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22444545

RESUMEN

BACKGROUND: Klebsiella pneumoniae liver abscess (KLA) is an emerging infectious disease caused by the virulent K pneumoniae strains of capsular serotype K1 and commonly associated with diabetes mellitus. Recurrent KLA is rarely reported and the mechanism of recurrence is uncertain. In this study we evaluated both phagocytosis by neutrophils and serum killing ability of serum from recurrent K1 KLA patients compared to normal healthy subjects (NHS). METHODS: This prospective study included six cases of recurrent K1 KLA consisting of three male and three female patients with a mean age of 67.2 years (range, 56-88 years). The different serotypes of K pneumoniae were reacted with serum from patients with recurrent KLA and NHS. Subsequent phagocytosis by neutrophils was determined using flow cytometry and serum killing assays were performed. RESULTS: The most common underlying disease in patients with recurrent KLA was diabetes mellitus, occurring in about 83.3% (5/6) of patients. The antibiogram of the strains associated with recurrent KLA remained uniquely resistant to ampicillin. The average percentage derived from the serum killing assays showed serotype K1 and K2 resistance to serum from NHS (1281% and 621%, respectively); however, serum susceptibly was observed in the serum of patients with recurrent K1 KLA (0.3% and 1.1%, respectively). A significant increase in neutrophil phagocytosis of serotype K1 was observed following opsonisation with serum from patients with recurrent KLA compared with serum from NHS (p = 0.008). No significant difference in the phagocytic rate of non-K1/K2 or K2 serotypes was observed between NHS and patients with recurrent KLA (p = 0.76 and p = 0.132, respectively). CONCLUSION: These preliminary results showed possible immunologic protection in patients with recurrent KLA due to increasing opsonization and serum killing.


Asunto(s)
Anticuerpos Antibacterianos/inmunología , Cápsulas Bacterianas/análisis , Actividad Bactericida de la Sangre , Infecciones por Klebsiella/inmunología , Klebsiella pneumoniae/inmunología , Absceso Hepático/inmunología , Proteínas Opsoninas/inmunología , Anciano , Anciano de 80 o más Años , Antígenos Bacterianos , Cápsulas Bacterianas/inmunología , Femenino , Citometría de Flujo , Humanos , Infecciones por Klebsiella/microbiología , Klebsiella pneumoniae/química , Absceso Hepático/microbiología , Masculino , Persona de Mediana Edad , Neutrófilos/inmunología , Fagocitosis , Polisacáridos Bacterianos , Estudios Prospectivos , Recurrencia
3.
J Clin Microbiol ; 45(1): 266-9, 2007 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-17093025

RESUMEN

A nosocomial pyogenic liver abscess caused by an extended-spectrum beta-lactamase-producing Klebsiella pneumoniae isolate presented in a man with adenocarcinoma of the stomach. The K. pneumoniae strain isolated from blood and liver aspirate cultures after antibiotic therapy for recurrent bacteremia was resistant to all extended-spectrum beta-lactams except imipenem and differed from K. pneumoniae strains causing community-acquired liver abscesses.


Asunto(s)
Infección Hospitalaria/microbiología , Infecciones por Klebsiella/microbiología , Klebsiella pneumoniae/aislamiento & purificación , Absceso Piógeno Hepático/microbiología , beta-Lactamasas/metabolismo , Adenocarcinoma/complicaciones , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Bacteriemia/tratamiento farmacológico , Bacteriemia/microbiología , Infección Hospitalaria/tratamiento farmacológico , Resultado Fatal , Humanos , Infecciones por Klebsiella/tratamiento farmacológico , Klebsiella pneumoniae/efectos de los fármacos , Klebsiella pneumoniae/enzimología , Absceso Piógeno Hepático/tratamiento farmacológico , Masculino , Persona de Mediana Edad , Neoplasias Gástricas/complicaciones , Resistencia betalactámica
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